It will be readily understood that, as the interior of the container is filled, the inner atmosphere thereof must be evacuated towards the outside, driven by the arrival of the solid products; now, this atmosphere is precisely considerably laden with dust and particles in suspension which spread spontaneously in the ambient medium.
Attempts have been made to overcome this drawback by associating the principal discharging sleeve, through which the bulk material is poured into the container, with an outer concentric sleeve defining with the first a space in the form of a cylindrical ring allowing the dust to escape from the container, said space terminating in filtration means associated with suction means.
Installations of this known type are far from being satisfactory, as they represent a complex, expensive structure whose operation is difficult to master; in fact, in order to ensure reliable efficiency of such systems, an artificial draught of the particle-laden atmosphere must be provoked, which causes a parasitic entrainment of the dispersed pulverulent products and a rapid clogging of the filters.
It is a first object of the invention to overcome this drawback by eliminating any penetration in the ambient atmosphere of particles in suspension escaping from the interior of the container being loaded.
Another object of the invention is to allow automatic, simple and reliable recovery of the particles of the pulverulent product which are recycled and return in the principal flow of the material poured.